trebloc Posted October 28, 2007 Share Posted October 28, 2007 I have a Yamaha FZS Fazer 600 1999. I have noticed that when started the exhaust downpipe from number two cylinder never warms up. I assume that the combustion in that cylinder is faulty. I have checked the spark plugs, ignition system, valve clearances, carb sync etc and everything is ok. If you have any advise please let me know. Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2007 Share Posted October 28, 2007 It cannot be firing on that cylinder. If the exhaust is cold then there is a fault. Take the plug out and ground it on the engine, then when turning it over see if there is a spark. Don't hold on to the plug to do this. I suspect that there is no spark and the plug lead is faulty. Spark plugs are also known to fail. Link to comment Share on other sites More sharing options...
trebloc Posted October 28, 2007 Author Share Posted October 28, 2007 Thank you for your quick reply I have checked all the ignition circuit and spark plugs for the correct firing and all is ok. I have even changed the two coils around and the same problem persists in the same cylinder. Today i have done a compression test and all the readings are 140psi which is very low. I wouldn't of thought the pistons or rings are worn because it has only done 9500 miles. Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2007 Share Posted October 28, 2007 I suppose that the carb for that cylinder has some fuel in it? Link to comment Share on other sites More sharing options...
jinxed Posted October 29, 2007 Share Posted October 29, 2007 I suppose that the carb for that cylinder has some fuel in it? To check if fuel is getting into this cylinder, take the plug lead off the suspect cylinder and run the engine for a short while. Remove the plug and check for petrol. Apart from compression, did you check that the plug hole "sucks & blows" when you rotate the engine by hand? (I.e. checking that the valves are operating.) Link to comment Share on other sites More sharing options...
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